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Experimental and computational study on the reactivity of 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile, a key intermediate for the synthesis of tribenzoporphyrazine bearing peripheral methyl(3-pyridylmethyl)amino substituents.

Goslinski T, Dutkiewicz Z, Kryjewski M, Tykarska E, Sobotta L, Szczolko W, Gdaniec M, Mielcarek J - Monatsh. Chem. (2011)

Bottom Line: The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction.The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion.This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring. .

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.

ABSTRACT

Abstract: An earlier developed alkylating path leading to tetraalkylated diaminomaleonitrile derivatives was explored. Attempts to explain the reactivity of the representative dialkylated diaminomaleonitrile 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile during the alkylation reaction were performed using X-ray and density functional theory (DFT) studies. The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction. The values of the Fukui functions and condensed softness for electrophilic attack calculated from Mulliken, Löwdin, and natural population analyses closely corresponded to the experimental observations. When 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile disodium salt was treated with dimethyl sulfate at lower temperatures the alkylation reaction prevailed, whereas at higher temperatures the alkylating agent acted as a hydride anion acceptor, which favored the elimination reaction. The tetraalkylated dinitrile 2,3-bis[methyl(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile was used in the synthesis of tribenzoporphyrazine bearing methyl(3-pyridylmethyl)amino groups, which was subsequently subjected to solvatochromic and metallation studies. The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion. This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring.

Graphical abstract: .

No MeSH data available.


Synthesis of dinitriles 4–6, tribenzoporphyrazine 8, and phthalocyanine 9. TFA trifluoroacetic acid
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Fig1: Synthesis of dinitriles 4–6, tribenzoporphyrazine 8, and phthalocyanine 9. TFA trifluoroacetic acid

Mentions: Sequential double-reductive alkylation of DAMN (1, Fig. 1) was employed to yield 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile (5) following a method elaborated by the Sheppard [1] and Barrett–Hoffman teams [3]. The intermediates 2-amino-3-[(3-pyridylmethylidene)amino]-2(Z)-butene-1,4-dinitrile (2) and 2-amino-3-[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile (3) have been previously obtained and characterized [16]. It was found that alkylation reaction of 5 using dimethyl sulfate in the presence of sodium hydride in the temperature range −20 to −10 °C led to the alkylated 2,3-bis[methyl(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile (6) with 13% yield. The product was isolated as red–brown oil, which was very unstable during attempted crystallization. Moreover, when the reaction was performed at 0 °C, imine 2-[(3-pyridylmethyl)amino]-3-[(3-pyridylmethylidene)amino]-2(Z)-butene-1,4-dinitrile (4) was isolated alone or in the mixture of products, yielding up to 45%. Attempts to elucidate this observation are reported later in this paper.Fig. 1


Experimental and computational study on the reactivity of 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile, a key intermediate for the synthesis of tribenzoporphyrazine bearing peripheral methyl(3-pyridylmethyl)amino substituents.

Goslinski T, Dutkiewicz Z, Kryjewski M, Tykarska E, Sobotta L, Szczolko W, Gdaniec M, Mielcarek J - Monatsh. Chem. (2011)

Synthesis of dinitriles 4–6, tribenzoporphyrazine 8, and phthalocyanine 9. TFA trifluoroacetic acid
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4495027&req=5

Fig1: Synthesis of dinitriles 4–6, tribenzoporphyrazine 8, and phthalocyanine 9. TFA trifluoroacetic acid
Mentions: Sequential double-reductive alkylation of DAMN (1, Fig. 1) was employed to yield 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile (5) following a method elaborated by the Sheppard [1] and Barrett–Hoffman teams [3]. The intermediates 2-amino-3-[(3-pyridylmethylidene)amino]-2(Z)-butene-1,4-dinitrile (2) and 2-amino-3-[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile (3) have been previously obtained and characterized [16]. It was found that alkylation reaction of 5 using dimethyl sulfate in the presence of sodium hydride in the temperature range −20 to −10 °C led to the alkylated 2,3-bis[methyl(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile (6) with 13% yield. The product was isolated as red–brown oil, which was very unstable during attempted crystallization. Moreover, when the reaction was performed at 0 °C, imine 2-[(3-pyridylmethyl)amino]-3-[(3-pyridylmethylidene)amino]-2(Z)-butene-1,4-dinitrile (4) was isolated alone or in the mixture of products, yielding up to 45%. Attempts to elucidate this observation are reported later in this paper.Fig. 1

Bottom Line: The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction.The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion.This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring. .

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Technology of Drugs, Poznan University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan, Poland.

ABSTRACT

Abstract: An earlier developed alkylating path leading to tetraalkylated diaminomaleonitrile derivatives was explored. Attempts to explain the reactivity of the representative dialkylated diaminomaleonitrile 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile during the alkylation reaction were performed using X-ray and density functional theory (DFT) studies. The condensed Fukui functions accompanied by softness indices were found to be useful in explaining its reactivity observed during the reaction. The values of the Fukui functions and condensed softness for electrophilic attack calculated from Mulliken, Löwdin, and natural population analyses closely corresponded to the experimental observations. When 2,3-bis[(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile disodium salt was treated with dimethyl sulfate at lower temperatures the alkylation reaction prevailed, whereas at higher temperatures the alkylating agent acted as a hydride anion acceptor, which favored the elimination reaction. The tetraalkylated dinitrile 2,3-bis[methyl(3-pyridylmethyl)amino]-2(Z)-butene-1,4-dinitrile was used in the synthesis of tribenzoporphyrazine bearing methyl(3-pyridylmethyl)amino groups, which was subsequently subjected to solvatochromic and metallation studies. The changes observed during metallation seem to result from the coordination of the 3-pyridyl group by a palladium ion. This could influence the configuration of the methyl(3-pyridylmethyl)amino moiety, causing more effective donation of a lone pair of electrons from peripheral nitrogen to the macrocyclic ring.

Graphical abstract: .

No MeSH data available.